“NGTC”是“國(guó)家珠寶玉石質(zhì)量監(jiān)督檢驗(yàn)中心”(National Gemstone Testing Center)暨“國(guó)家寶石監(jiān)測(cè)培訓(xùn)中心”(National Gemstone Training Center)英文的縮寫。